Ok, here is a bit of thread necromancy to give a quick tip for those willing to play the demo in the opening post. The mod appears to be designed for Warcraft TFT 1.23 which was the latest version at the time of release. Trying to run it on earlier versions will generally result in a fatal error message and later versions won't start loading the map.

Luckily, there is a well-known utility that lets us work around the issue. Go here and download Warcraft Version Switcher as well as patch files 1.23 and 1.26, the latter being current version at the time of this post. Use the utility as per instruction on its web-site to switch your Warcraft client to 1.23 to play DoC, then use the same utility to revert back to 1.26 to play Battle.net or generally be up-to-date.

Invented this by trial-and-error and it was completely worth the trouble. Even after all this years, DoC is impressive.

Update:
Silly me, the tip above is meaningless as long as the download link in the opening post is not functional. Full credit to user Verctor of samods.org, you can download the demo of Dawn of Chaos from architect.nexfiles.com (direct link). Additionally, I do have a copy so you can PM me for an upload in case the link dies.

P.S. Does anyone know the developers' current e-mails? Couple of weeks ago I dropped them a message regarding a donation and they won't reply.